[update]

main.py

@@ -28,8 +28,9 @@ def main():
                                ):
         model_group = model_dict.get(model_name)
         if model_group is None:
-            for k, mg in model_dict.items():
-                del mg["model"]
+            for k in list(model_dict.keys()):
+                del model_dict[k]
+
             model_dict[model_name] = {
                 "model": M2M100ForConditionalGeneration.from_pretrained(model_name),
                 "tokenizer": M2M100Tokenizer.from_pretrained(model_name)